I design one form with TAB control I place sub form in tab control, the Sub
form is base on datasheet view, I add one unbound control text field which
enabled property set to NO, this control source property base on two other
column value like I have two bound(Table) fields I want to show the addition
of this field at runtime in this unbound field, every thing is perfect here
but I also want SUM of this unbound feild in datasheet view, I try many
things but It did not show sum of this unbound field, only Count function
work(Total Row option in 2007) for this field even I set format to general
number. how I achieve this functionality.

Thank you